Is vitamin C deficiency associated with worse outcomes in hospitalized patients with ulcerative colitis? A prospective observational study.

Abstract

Background and Aim: Vitamin C deficiency is well recognized to occur in a small proportion of the population with inflammatory bowel disease. Vitamin C plays an important role in wound healing, from neutrophil apoptosis and clearance through to collagen formation. Our group showed a prevalence of vitamin C deficiency of 33% in a review of upper gastrointestinal bleeding, suggesting that the importance of vitamin C is clinically relevant in the gastrointestinal bleeding scenario. In light of this, we hypothesized that vitamin C deficiency may be associated with worse outcomes in patients with ulcerative colitis (UC) flares. Method(s): This was a preliminary prospective, single-center, observational study performed at a tertiary health network. All patients with UC hospitalized due to a flare of their colitis were evaluated for this study. Recruitment commenced on 1 March 2021 and was completed on 7 May 2021. Serum vitamin C level was measured as an early-morning, fasted test early in the admission. Other nutritional markers, including body mass index (BMI), iron studies, and levels of albumin, zinc, vitamin B12, folate, and vitamin D, were also collected. Markers of severity included Truelove and Witts criteria, C-reactive protein (CRP) level, albumin level, Mayo score, Oxford score, need for colectomy, and death. Result(s): We identified 20 patients, three of whom were excluded from the study as they did not have a vitamin C measurement performed. Therefore, 17 patients met the inclusion criteria. Six patients had a new diagnosis of UC. Fourteen patients had severe disease and three had moderate disease based on Truelove and Witts criteria. Fasting vitamin C levels were recorded within the first 2 days for 15/17 patients. Two patients had low vitamin C levels. Fifteen patients had iron studies performed, with 11 demonstrating iron deficiency, making it the only commonly found micronutrient abnormality in our cohort. Two of 11 patients tested for vitamin D had low levels. Two of 14 patients tested for vitamin B12 were deficient. None of the 12 patients tested for folate were deficient. Three of 16 patients tested for zinc levels were deficient. Three, 10, and seven patients had low, normal, and high BMI, respectively (normal, 18.5-24.9 kg/m2, as per the World Health Organization). The patients with low BMI all had Mayo 3 findings on sigmoidoscopy. Eight of 17 patients had low albumin levels (<35 mg/L) on presentation. The two vitamin C-deficient patients both had severe colitis on Truelove and Witts criteria, elevated BMIs, and low iron studies but otherwise normal micronutrient profiles. One had a raised CRP level, low albumin level, and Mayo 3 colitis on flexible sigmoidoscopy; sigmoidoscopy was not performed in the other patient. Neither patient met Oxford criteria for rescue therapy. Of note, the zinc-deficient patients had low to low-normal BMI (18.4-21 kg/m2) and had severe colitis according to Truelove and Witts criteria. Two patients met Oxford criteria for rescue therapy in this study. The only micronutrient deficiency detected in either of these patients was vitamin D deficiency. No patients required colectomy, and there were no deaths. Conclusion(s): There was a low prevalence of vitamin C deficiency in this cohort of patients with a flare of UC. They did not meet Oxford criteria for rescue therapy. Vitamin C-deficient patients also had associated iron deficiency. Iron deficiency was the most common micronutrient deficiency found, with other micronutrient deficiencies being uncommon. Further research with larger study populations is required to evaluate whether vitamin C deficiency is associated with worse outcomes in UC flares.